Full hybrid vehicles may have brake-by-wire systems to facilitate coordinated or series regenerative braking. Brake-by-wire system architectures in production generally fall under one of 3 categories: electromechanical systems, which utilize electronic calipers; electro-hydraulic systems, which typically utilize a high-pressure accumulator with analog hydraulic valves to generate pressure that is applied to individual or multiple wheels; and active booster based systems, which utilize an active boosters (either vacuum or hydraulic) to generate controlled boosted hydraulic pressure, via a conventional brake master cylinder, that is applied to the wheel or wheels. These system architectures each have advantages and disadvantages in areas such as cost, package, durability and complexity. For example, the vacuum-based brake-by-wire system may be characterized by lower cost with some functional advantages but may lack other functionalities that the other systems provide. The vacuum-based brake-by-wire system typically requires an active booster in conjunction with a vacuum supply (electric vacuum pump) and a pedal-mounted brake feel simulator unit. This arrangement may prevent independent front/rear braking pressure control and may have other disadvantages as well.
Therefore, an electro-hydraulic brake-by-wire system and method are needed in which the rear hydraulic brakes of a conventional vacuum-based brake-by-wire system are replaced with electronic brakes and the active booster, vacuum pump and pedal-mounted simulator unit of the vacuum-based brake-by-wire system are replaced by an electronic booster which may include an integrated pedal feel simulator to provide cost, package and functional improvements.